Electrical control system.



W. N. MGUOMB.

ELECTRICAL CUNTROL SYSTEM.

APPLIUA'IION FILED JUNE 5.1911

Patented Jan. 5, 1915.

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W. N. MOCOMB.

ELECTRICAL CONTROL SYSTEM. APPLICATION TILED JUNE 5. 1011 1,123,341., Patented Jan. 5, 1915.

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WILLIAM N. mooma, or NEW YORK, N. Y.

ELECTRICAL CONTROL SYSTEM.

Specification of Letters Patent.

Patented Jan. 5, 1915.

Application filed June 5, 1911. Serial No. 631,309.

To all whom it may concern:

Be it known that I, WILLIAM N. MCCOMB, a citizen of the United States, and a resident of New York city, in the county of New York and State of New York, have in- .vented certain new and useful Improvements in Electrical Control Systems, of which the following is a specification.

In certain classes of work, such as in electric signs, thermal switches or thermo flashers, as they are known, are used to a considerable extent for flashing lamps or alternately making and breaking circuits through other electro-responsive devices. Thermal switches are for the most part more desirable than mechanically operated switches for many reasons-they consume less current, they are less liable to get out of order, and they are wholly automatic and self-contained. Thermo flashers are of limited capacity, however, and are not well adapted for flashing a very large number of lamps or for doing other very heavy work.

The object of the present invention is to utilize a thermal switch for controlling a circuit through a bank of lamps or other electro-responsive devices, without actually throwing the load on the thermal switch. This result I have accomplished by utilizing a circuit closer for doing the actual work of making and breaking the circuit through the electro-responsive' devices, and in placing this circuit closer under the control of the thermal switch.

Another object of my invention is to secure by means of a single device, different combinations or methods of flashing the lamps or operating other electro-responsive devices. To accomplish this object I preferably provide two or more circuit closers, and means, such as a manually operated switch for placing all the circuit closers under the direct control of the thermal switch or one circuit closer under the control of the thermal switch and the other circuit closers under the control of the first circuit closer.

In a preferred form the invention consists of a pair of electro-magnetic circuit closers, a thermal switch, contact means operated by one of the circuit closers to complete a circuit through the thermal switch and also through the second closer, and a switch for thus placing the second circuit closer either under control of the first cirthermal switch.

Various other objects and features of my invention will appear as the specification proceeds.

In the accompanying drawings I have illustrated a preferred embodiment of my invention but I would have it understood that various changes and modifications may be made therein without departing from the spirit and scope thereof And while I have illustrated the invention as in use for flashing lamps such as in an electric sign, I would have it known that it is not limited to this particular use.

In the drawings: Figure 1, is a more or less diagrammatic view of a practical embodiment of the invention with the lamp circuits open. Fig. 2, is a like view with the lamp circuits closed and the lamps burning. Fig. 3 is a similar view illustrating the operation of the device when the controlling switch is actuated to place one circuit closer under the control of the other. In this instance one lamp circuit is closed while the other 'lamp circuit is open. Fig. 4 is a detail view to illustrate the operation of the thermal switch.

The same reference characters refer to like parts throughout the several views.

In the present embodiment of the invention I have illustrated only two circuit closers, 1, and 2, but more than these may be employed, if desired, as will appear later. These circuit closers preferably simply consist of an electro-magnet or solenoid coil 3, provided with-a solenoid rod or core 4, attached to a switch lever 5, which lever is pivoted on the center 6. The switch lever is arranged to engage with a stationary Contact Z", and to reduce the spark and protect the switch points, the switch lever may carry a spring arm 8, provided with a carbon contact 9 to engage with a corresponding carbon contact 10 on the fixed switch point. The result of this arrangement is that in the closing and opening of the switch the carbon points make contact before and break contact after the main switch points thus protectin the main switch points from injurious spar ing.

Controlling the circuit closers there is a thermal switch or thermo flasher 11. The construction of this thermal switch may also vary, but it is here shown as consisting of a bar 12 of some suitable material possessing a relatively high co-efiicient of expansion, a heating coil 13 of high resistance surrounding or in close proximity to the expansive bar, and a stationary though preferable adjustable contact point 14, adapted to be engaged by the bar when the same has expanded to a certain extent.

, 'When the device is used in a three wire system, the line wires 15, 16 and 17 are connected to the res ective positive, neutral and negative termina s 18, 19 and 20, preferably in the arrangement shown. The circuits containing the lamps 21 or other electroresponsive devices are designated 22 and 23, one circuit being controlled by each circuit closer. (By adding other circuit closers, additional lamp circuits may be controlled).

A neutral or common return may be utilized in the two lamp circuits, substantially as shown. Current is led to the lamp circuits by means of the three conductors 24, 25, and 26 connected with the respective positive, neutral and negative terminals 27, 28, and 29 arranged preferably as illustrated.

To insure the proper operation of the thermals'witch, and in some cases to control the operation of the second circuit closer, I preferably provide contact means, which means may be operated by the first circuit closer. In the present instance this contact means is shown in the form of an arm or projection 30 extending to the rear of the pivotal support of the switch lever and carrying the contact fingers 31 and'32 to engage with the fixed contacts 33 and 34 respectively.

For the purpose of controlling the second circuit closer and to secure a variation in the operation of the device, 1 preferably provide means such as a two-point switc 35 for placing the second circuit closer (or circuit closers, if there are more than two) either under the control of the first circuit closer, or under the direct control of the thermal switch.

In the operation of the device, assuming the switch 35 to be in the. position shown in Figsil and 2, the actionis as follows: Cur-- rent from the positive side of the line flows to the terminal 18, thence by an internal connection 36 to the switch lever 5 (connecting with said switch lever and preferably at the pivotal support thereof) of the first circuit closer. When the first circuit closer is deenergized, as in Fig. 1, the finger 32 of the contact means is in engagement with the stationary contact 34 so that the current flows from theswitch lever by way of the contact finger 32, stationary contact 34, conductor 37, to the heating coil 13 of the thermal switch, through this heating coil by way of a short connection 38 to the coil 3 of the first circuit closer. The other terminal of this coil is by means of a short conductor 39 connected with the neutral terminal 19. After leaving the heating coil, the current divides at the point 40 and flows by way of a branch 41 to the switch point 42, switch lever 35, connection 43, to the coil of the second circuit closer, and thence by a conductor 44 back to the neutral terminal 19. In this first position then, both the circuit closers are in series with the high resistance circuit of the thermal switch. The relatively high resistance of this heating coil of the thermal switch prevents sufficient curcurs the heating coil is short-circuited and the current flows direct to the stationary contact 14 by wayof a branch conductor 45 through the bar (which thus forms a low resistance circuit whose actual resistance is practically ml) to the connection 46 of both the bar and the heating coil, thence by way of-conductors 38 and 39, through the coil of the first circuit closer. .A portion. of the current divides at the point 40 and flows by way of conductor 41, switch lever 35, and conductors 43 and 44, through the coil of the second circuit closer. A circuit of low resistance is thus provided through the coils of both the circuit closers, and consequently both circuit closers are energized and close the respective circuits controlled thereby.

When thefirst circuit closer is energized, the contact means is operated thereby to disrupt the circuit through the heating coil of the thermal switch, for when the circuit closer is energized, as shown in Fig. 2, the contact finger 32 is shifted away from the stationary contact 34. This positive break in the high resistance circuit of the thermal switch permits the expansive bar to cool off, and as itdoes so, it finally recedes from engagement with the stationary contact point 14, thereby breaking the low resistance circuit through the circuit closers. Both the high resistance and the low resistance circuits, through the circuit closers, arethus broken at this time, and both circuit closers consequently become deenergized. Upon the deenergiz'ation of the first circuit closer, the contact finger 32 is again brought into engagement with the stationary contact 34, thereby restablishing the high resistance circuit through the thermal switch. Under the influence of the heat generated by this high resistance circuit the thermal switch again establishes a low resistance circuit through the circuit closers, and the operations just described are continued indefinitely.

When the circuit closers are energized, the circuits to the lamps are as follows: The

positive side of the line is connected with the switch lever of the first circuit closer by means of a connection 36, already described. When the circuit closer is energized, and the switch lever is in contact with the stationary switch point 7, the current flows from the switch lever through the stationary switch point 7 and a cross connection 47 to the positive terminal 27, thence by the conductor 24 to one side of the lamp circuit 22, through the lamps or other electro-responsive devices to the other side of the lamp circuit 22, and by return conductors 25 and 44 to the neutral terminal 19. When the second circuit closer is energized, current flows from the negative terminal 29 by way of a conductor 48 to the switch lever of the circuit closer, thence by way of the stationary switch point 7, and a short connection 49 to the negative terminal 29, and from here the conductor 26 to one side of the other lamp circuit 23, through the lamps and by the common return conductors 25 and 44 back to the neutral terminal 19.

According to the arrangement just described, each circuit closer independently controls an independent lamp circuit but both circuit closers are under control of the thermal switch so as to act in unison with each other. A variation from this operation is obtained by placing the second circuit closer (or circuit closers, as the case may be) under control of the first circuit closer. This is done by throwing the switch lever 35 over to the switch point 50, as indicated in Fig. 3. Then when the first circuit closer is deenergized and the contact finger 31 is in engagement with the stationary contact 33, the current will flow by way of conductor 36, finger 31, stationary contact 33, the short connection 51, to the switch point 50, thence by way of switch lever 35, conductors 43 through the coil of the second circuit closer, and back to the neutral side of the line by way of conductor, 44. The second circuit closer will thus, by reason of the contact means which is operated by the first circuit closer, be energized when the first circuit closer is deenergized. But when, through the operation of the thermal switch, the first circuit closer is energized, the circuit through the second circuit closer will be broken between the finger 31 and contact 33. In this way the circuit closers will alternate in operation, one becoming energized when the other is deenergized, and vice versa. This arrangement is particularly useful in double faced electric signs, the faces of which are usually flashed in alternation.

When operating on a two-wire circuit, the device may be used without change by simply short-circuiting the positive and negative line terminals 18 and 20, as by means of a bridge connection 52, indicated in dotted lines in Fig. 2. In this casethe two line wires are connected to the two terminals 18 and 19. In operation on a two wire circuit, assuming that the first circuit closer is energized the circuit to the lamps is from terminal 18, conductor 36, switch lever 5, switch point 7, connection 47, terminal 27, connection 24 to one side of the lamps, through the lamps and back through connection 25, terminal 28 and conductor 44 1. In an electric control system, an elec tro-magnetic circuit closer, a second electromagnetic circuit closer, a thermal switch having a heating coil, contact means oper ated by the first circuit closer to complete a circuit through the heating coil of the thermal switch and a circuit through the coil of the second circuit closer, and a switch interposed between the contact means and the coil of the second circuit closer, which completes a circuit either through the contact means and the coil of the second magnetic circuit closer or through the thermal switch and the coil of the second magnetic circuit closer.

2. In an electric control system, an electromagnetic circuit closer, a thermal switch consisting of a heating coil and an expanslon bar, a second electromagnetic circuit closer, contact means to complete an energizing circuit through the coil of the second magnetic circuit closer and the heating coil of the thermal switch when the first circuit closer is deenergized, connections whereby the thermal switch acting under the influence of the heat generated therein short circuits its heating coil and completes an energizing circuit through its expansion bar and through the coil of the first circuit closer, the contact means then acting to rupture the circuit through the heating coil of the thermal switch, and said thermal switch acting due to the rupture of the circuit through said heating coil to break the energizing circuit through the coil of the first circuit closer.

3. In an electric control system, an electromagnetic circuit closer, a thermal switch, consisting of a heating coil and an expansion bar, a second electromagnetic circuit closer, contact means for completing a circuit through the heating coil of the thermal &

switch when the first circuit closer is de'e'nergized, connections whereby said thermal switch acting under the influence of the heat generated therein short circuits its heating coil and completes an energizing circuit through its expansion bar and through the coils of the two circuit closers, the contact means when the coils of the first circuit closer is energized acting to rupture the circuit through the heating coil of the thermal switch, and the thermal switch due to the rupture in the circuit of the heating coil thereof acting to rupture the energizing circuits through its expansion bar and through the coils of the circuit closers.

at. In an electric control system, a thermal switch, an electromagnetic circuit closer, a contact means actuated by said circuit closer, a second electromagnetic circuit closer, energizing circuits controlling the said circuit closers, and a switch and connections for simultaneously completing the energizing circuits through the coils of both of said electromagnetic circuit closers through the thermal switch, or for completing the energizing circuits through the said circuit closers in alternation respectively through the thermal switch and the contact means at will.

5. In an electric control system, a thermal switch, energizing circuits, a plurality of electromagnetic circuit closers in said energizing circuits under control of the thermal switch, and means cooperating with said thermal switch for completing the circuits through the said circuit closers simultaneously or in alternation at will.

Signed at New York city in the county of New York and State of New York this 22nd day of May A. D. 1911.

\VILLIAM N. MCCOMB.

Witnesses:

J EANNETTE SToRK, PHILIP S. MCLMAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatents,

, Washington, D. C." 

